Performance monitoring and stability testing of perovskite solar cells

Remec, Marko (author), Topič, Marko (mentor)

With high power conversion efficiencies already achieved in perovskite solar cells (PSCs), research is moving towards improving the stability of those devices. The primary focus of this thesis is on the stability analysis of perovskite-based solar cells under realistic operating conditions. The results of long-term outdoor monitoring are combined with indoor characterization results and systematically analysed to evaluate the operational performance and long-term outdoor behaviour of PSCs. Compared to conventional photovoltaics (PV), PSCs can exhibit a various, often high-magnitude, reversible changes in device performance. Two indoor ageing setups that enable the characterization of those effects are presented: the developed white LED (WLED), for characterization of single junction devices, and optimized bichromatic LED (BCLED), used for the testing of tandem solar cells. Seasonal operation is analysed and discussed for single-junction perovskite solar cells. Despite the good summer-to-summer stability of the devices, the seasonality observed in the Berlin climate is significantly more pronounced compared to silicon PV. We explain and interpret this behaviour by separating and explaining the different contributing factors: solar spectrum, device temperature, maximum power point tracking losses, and metastability effects. The metastability effects are observed in various perovskite compositions, but their dynamics and magnitude can vary. Analysis of how the magnitude of metastability differs in devices that share the same structure but use different hole transport layers (HTLs) is presented. To qualitatively and quantitatively investigate the effect of light-soaking effect we combined long-term outdoor monitoring results with energy yield modelling for both single junction perovskite and perovskite-silicon tandem solar cells. The presented long-term outdoor data for the lab-scale PSC devices, demonstrates the potential of PSC technology to reach the operational lifetime requirements of current commercialized PV technologies. However, it is important to improve our understanding of the processes behind their unique real-world behaviour to achieve accurate data interpretation and energy yield forecasting.

• Language: English
• Keywords: Perovskite solar cells, outdoor monitoring, indoor characterization setups, light-soaking effect, perovskite seasonality
• Work type: Doctoral dissertation
• Typology: 2.08 - Doctoral Dissertation
• Organization: FE - Faculty of Electrical Engineering
• Year: 2025
• PID: 20.500.12556/RUL-177726
• COBISS.SI-ID: 264647939
• Publication date in RUL: 05.01.2026

Secondary language

• Language: Slovenian
• Title: Spremljanje zmogljivosti in preizkušanje stabilnosti perovskitnih sončnih celic

Abstract

Perovskitne sončne celice (PSC) že dosegajo visoko učinkovitost pretvorbe energije, raziskave se zato zdaj osredotočajo na stabilnost teh naprav. Glavni poudarek te doktorske disertacije je na analizi stabilnosti perovskitnih sončnih celic v realnih pogojih delovanja. Rezultati dolgoročnega spremljanja delovanja PSC v realnih pogojih so združeni z rezultati laboratorijske karakterizacije in sistematično analizirani. Perovskitne sončne celice, za razliko od silicijevih, pogosto izkazujejo metastabilnost – reverzibilne spremembe zmogljivosti delovanja, pri čemer nastopata in se izmenjujeta tako degradacija kot regeneracija. Predstavljena sta dva sistema, ki omogočata laboratorijsko karakterizacijo metastabilnosti: WLED (angl. white LED) za karakterizacijo enospojnih, ter BCLED (angl. bichromatic LED), za karakterizacijo tandemskih sončnih celic. Vpliv sezonskih ciklov na delovanje PSC je podrobno obravnavan na podlagi seta podatkov z rezultati več kot štirih let spremljanja delovanja PSC pod realnimi pogoji. Razlogi za te spremembe so pojasnjeni s prispevki različnih dejavnikov: spremembe sončnega spektra, delovna temperatura celic, izgube pri sledenju MPP in metastabilnost PSC. Od metastabilnih efektov je pri testiranih PSC najbolj izražen efekt svetlobne regeneracije (angl. »light-soaking effect (LSE)«), reverzibilni proces, ki povzroči da učinkovitost PSC v temi pade in se nato regenerira ob osvetlitvi. Kako različne strukture PSC vplivajo na metastabilnost in intenzivnost ter dinamiko teh efektov, je prikazano na PSC, ki se v strukturi razlikujejo le v plasti za transport vrzeli. Podrobna evalvacija vpliva LSE je predstavljena z uporabo modela energijskega donosa (angl. »energy yield«, EY). Analiza dnevne dinamike izgub je pokazala, da je LSE odvisen od kumulativnega dnevnega sončnega obsevanja in temperature. EY algoritem je bil nato nadgrajen z upoštevanjem pridobljenih rezultatov tako, da upošteva izgube zaradi LSE. Predstavljeni dolgoročni podatki o spremljanju stabilnosti PSC pod realnimi pogoji delovanja, predstavljajo potencial te tehnologije sončnih celic. Napovedi so optimistične, tako glede učinkovitosti delovanja kot tudi doseganja ciljev zahtevane življenjske dobe, ki jih zahtevajo trenutno komercializirane PV tehnologije. Prikazani rezultati kljub temu poudarjajo potrebo po natančni interpretaciji zbranih podatkov, bodisi za potrebo napovedovanja učinkovitosti pretvorbe energije ali oceno življenjske dobe.

• Keywords: Perovskitne sončne celice, spremljanje delovanja sončnih celic na prostem, laboratorijski sistemi za karakterizacijo, učinek svetlobne regeneracije, vpliv sezonskih ciklov na delovanje perovskitnih sončnih celic